[libcxx-commits] [libcxx] [libc++] Fix UB in <expected> related to "has value" flag (#68552) (PR #68733)

[A. Jiang via libcxx-commits]

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================
@@ -893,11 +854,15 @@ class expected {
   }
 
 private:
-  struct __empty_t {};
----------------
frederick-vs-ja wrote:

I think the intent is that when the union is value-initialized, we can only zero-initialize the `__empty_` member whose size is only 1 byte,

https://github.com/llvm/llvm-project/pull/68733